Distinct mechanisms for the impact of distraction and interruption on working memory in aging

Interference conceptual framework.

Experimental paradigm. All participants performed 4 tasks, which were blocked and counterbalanced.

Working memory accuracy and impact of interference. (A) Participants performed best in the no interference task (NI), followed by the distractor task (DS), and then the interruptor task (IS) (all comparisons are significantly different, p<.05). The older participants performed with a lower WM accuracy on all tasks. (B) Older participants have a greater impact on WM performance by both the distractor (DS) and the interruptor (IS), when corrected by their performance without interference (p<.05). Note: Asterisks represent significant differences between age groups.

Incidental long-term memory recognition. Older participants recognized interfering stimuli presented in the experiment more than younger adults and remembered them as well as the cues stimuli. Note: Single asterisks represent significant differences from 0, and double asterisks represent significant differences between ages/conditions.

Grand-averaged event-related potentials to intervening stimuli. (A) GAV ERPs from younger participants for Distractor stimuli (DS), Interruptor Stimuli (IS) and passively viewed intervening stimuli (PV). (B) ERPs from older participants. (C) N170 latency measures to intervening stimuli. Both younger and older participants significantly enhanced the interruptors (earlier peaks compared to passively viewed intervening stimuli). Unlike younger adults, older participants also showed enhancement for the distracting stimuli. (D) Comparisons of N170 latency attentional modulation indices between age groups. Older participants allocated more attention towards distractors than younger participants (suppression index), but did not differ in attention allocated towards interruptors (enhancement index).

Neurobehavioral correlations of the N170 latency attentional modulation indices. In both (A) younger and (B) older age groups, participants that enhance the interruptor more (upper panels) perform worse on the WM task. Likewise, participants that suppress the distractor more (upper panels) perform better on the WM task. Note: More positive value on the x-axis indicate greater enhancement above baseline or greater suppression below baseline.